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kgeiger writes "The Sprite project is testing the feasibility of chip-sized spacecraft. 'Rather than hand building one-of-a-kind spacecraft, we envision constructing spacecraft on wafers in much the same way that common integrated circuits are made today. During fabrication, solar cells and other components would be incorporated with microelectromechanical systems techniques. Instead of exhaustively testing each part, as is done with current spacecraft, engineers will be able to monitor Sprite quality in a less labor-intensive fashion by using statistical process control, testing a few chips from each batch to make sure they meet specifications.' The project's goal is to deploy true 'smart dust,' comprised of 5- to 50-mg single-sensor spacecraft capable of forming deep-space sensor arrays."

Meh, In the long run as long as they are on an outward trajectory we will never run into them. Even in system they could be save if their trajectory puts them into a gravity well. Just avoid placing them in orbit and they will be fine.

You ever get your windshield smacked by something that fell off a truck (like gravel or rock) and catch up to the offender to get insurance info? I have, a fist size rock almost came through the glass and I and another motorist (also hit) caught up to the trucker to get his info.

So here we are on our little mud ball, and something like the Vogons suddenly show up to collect from us for destruction of something they value... or worse they assume it was a stealth attack on a craft that was just going about i

So here we are on our little mud ball, and something like the Vogons suddenly show up to collect from us for destruction of something they value... or worse they assume it was a stealth attack on a craft that was just going about it's business someplace far away from us.

Didn't they see the sign posted that reads "not responsible for damage caused by debris damaging your ship" it was posted in a locked box in a dark corner in the basement of an old ladies house. If they didn't take the time to read it, then that's not our fault either.

What happens when a human occupied vehicle crosses paths with one of these dead objects at 10,000km/h differentail speeds?

While I appreciate the sentiment (and agree), you really need to understand how amazingly, hugely, vastly much empty room there is in space. There are enormous calculations needed to hit something the size of jupiter, even if you start pointed in the right direction.

Let's say a 1km asteroid is 10,000 km away, and you yourself are in a 1km (cross-section) spacecraft. To not hit it, you have to aim to be 1km in any direction away from it--.5km from half of your body,.5km from half of its body. In other words, to hit it, you have to point anywhere within a 1km radius of dead-on. Assuming no course corrections, you have to be pointed within about.005 degrees of the object center, in every direction. Put another way, a sphere of radius 10,000km is billions of square kilometers of surface area, more than twice that of the earth, and you would have to hit around one square kilometer of it.

The moon, which is the only stellar object that could be accused of being close, is not 10,000km away; it's something more than 30x that far. At that range, the object could have a 30x greater cross-section and you'd still have that same tiny angular danger zone. Everything else is millions of km away. The only really clogged region (relatively speaking) is earth orbit, and that's because we have so much that we want to do and to leave in a relatively small space.

Is polluting the solar system still a bad idea? Sure, probably. However, to be honest, by the time our spaceflight capabilities are up to travelling to other planets in earnest, we maybe able to shield against large particulates, and we'll know approximately where they are. (There's not much in the way of interference in space like there are in wind and water; there's solar wind, gravity wells, and inertia, and not much else.) The debris is also comparable to what you might expect from asteroid collisions, comet trails, and the like, which might be substantially harder to track. More importantly, there's a lot of science to be done before we're ready for all that, and this is at least partially helping progress that. Maybe.

The flaw in your reasoning is that there are very few interesting places in the solar system to go, so despite the very large volume available for navigating around these obstacles it's quite a bit more likely that a later space mission will be aiming for the exact same tiny angular zone as a previous one. It's similar to the current situation with satellites in Earth orbit - I occasionally hear about congestion in the geostationary orbits despite there being lots of potential orbits around the earth, some orbits are simply more desirable than others.

Don't get me wrong, I understand that there are complexities I'm glossing over (consecutive launch opportunities to the same destination not passing through the same space as each other, for example). But when you said:

The only really clogged region (relatively speaking) is earth orbit, and that's because we have so much that we want to do and to leave in a relatively small space.

you glossed over the fact that any well-explored destination in the solar system is destined to become a "clogged region" for exactly the same reason that Earth is now. Compared to the volume of space contained in the Solar System, the interesting destinations represent a "relatively small space" not significantly larger than Earth's orbital zone.

While it's true we may end up going back to the same places over and over again, you aren't likely to see congestion until long after any particular location is settled--or at least manned. The resources necessary for interplanetary travel are enormous, so commercial satellites and unnecessary debris will only occur when there is local manufacturing. Local manufacturing isn't likely to be feasible without getting people there on a long-term basis, which is full of logistical hurdles we haven't crossed yet

It was said during a televised interview, and I liked it, so I made it my sig. My memory is that t it was on a major network like C-SPAN, and I assumed that it would be transcribed and on the internet shortly. You're the first person to point out that it's not on Google, and it caught me off guard; I'm kinda sad to suddenly be in [citation needed] territory. It may even bug me enough to change to something I can cite, but I'll keep looking for a while first. Thanks for

And, more importantly, what's going to happen to my beloved BIG ASS ROCKETS that make lots of noise and look wicked cool at takeoff? You can't very well film home video of a tiny rocket launch and edit it with "Rock Me Like a Hurricane" playing in the background, now can you? NOW CAN YOU?

The air force is capable of tracking things as small as 1 cm2, which is the size of these chips. Furthermore, you track and avoid them like everything else in orbit. Their orbital information is added to the huge databases that allow mission planners to use a safe trajectory. Proposed ChipSat missions like this are meant to act as an array that follows a common orbit.
As for mission lifetime, federal regulations specify that almost without exception, any assets you put in low earth orbit must be able to n

5mg is about the mass of a grain of sand, not all that disproportionate to a micrometeoroid. If the human carrying spaceship can't survive a collision with such a mass, I think we've got bigger things to worry about. Cluttering the orbit zones with this stuff may pose a problem from a "grit" perspective, but nothing that can't be solved with some wipers.

Much of the weight and size in spacecraft is not the instruments, it's the fuel and engine. I get that you need a lot less of both if you've got a small mass, but still, how are you going to move the thing around?

TFA says they'll need some crazy new propulsion system, so yeah, we won't be seeing chip ships any time soon, probably.

Could use some kind of miniaturized hall effect drive or some other electrodynamic propulsion. I'm not sure if it would scale down to this size, but theoretically electrodynamic tethering could make a system mobile with no propellant at all.

As long as they do not convert the mass I am using for my survival and, uhm, for my existence in the material plane (as in "my body"), I think we can get along- should they get any ideas of messing with my synapses though, I would like to have access to a kill switch.

Every time I see the beautiful pictures from a couple guys who put a camera in a balloon and send it 100,000 ft up, I always wonder how big of a rocket is the minimum needed to get something hand-sized or smaller into orbit.

I did some back-of-the-envelope calculations once and determined I wouldn't be launching anything from my backyard anytime soon. Has anyone else taken a closer look at this though?

Hmmm...interesting possibility. Fixed-frame ring of balloons, with the 'payload' center elevated slightly above the balloons? Get to a certain altitude, and the rocket kicks in - you're not starting from 0 m/s - and you don't have to have enough fuel for the entire launch. Remotely vent the balloons, pick it back up (because you installed GPS and transmitting capability) for re-use.

I always wonder how big of a rocket is the minimum needed to get something hand-sized or smaller into orbit. I did some back-of-the-envelope calculations once and determined I wouldn't be launching anything from my backyard anytime soon. Has anyone else taken a closer look at this though?

That's kind of like taking a closer look at the boiling point of water or the value of G - there's no point. The answer is well known. (And your BOTE is correct.)

Well if I make enough money someday, and something like this actually is feasible, albeit with lots of time and say a $20k rocket, then I'd much rather get a cheap $20k car and a satellite than a fancy $40k car.

So in that sense there's more reason (at least for me) to take a closer look at this than the value of G.

Ummm, you are aware of how weak the gravitational pull of a 50mg chip would be, right? Even quite a few of them. Sure, there'd be a little pull, but I'm pretty sure Alpha Centauri would effect them more.

Yes... but it took millions of years for something as massive as the sun to condense. These craft will have be lighter and have somewhat less gravity than the cloud of gas that gave birth to the Sun. By the time they form a compact ball, it's even possible that the US debt limit will have been raised.

Sure, saying those wafers are useless is premature, however, what about common-sized satellites and space probes?

Instead of building yet another mars rover, NASA should have used what it had and just build ten more Mars Exploration Rovers instead of one extremely expensive, completely new rover - with a whole new set of technical issues. All they would have had to do would be to build a new modular spacecraft to carry them with in a Delta IV or Atlas V - because the Delta II is no longer available.

Instead of building yet another mars rover, NASA should have used what it had and just build ten more Mars Exploration Rovers instead of one extremely expensive, completely new rover - with a whole new set of technical issues.

There are new technical issues because it's new tech. Just think for a moment about how much better digital cameras have gotten over the past 10 years. Sure, we could build 10 more MERs, but we'll get a lot more science value out of one new rover.

Nobody stops you from upgrading some parts while they are still on the ground - but a lot of the mechanical parts, the transfer stage, landing etc. won't need to be redeveloped, and even the upgraded parts will be easier to implement. You could also think about using modularized instruments that you can change depending on the needs of the mission.

Btw. rather than improved cameras, a better computer would do a whole lot more to improve the science output of the mars rovers, because it would enable a lot

It is probably impossible to thermally isolate and heat such a small spacecraft, since the ratio of surface area to volume is horribly large. So these things will be at a temperature of 3K, unless they are in sunlight.
I don't think that any battery will work for this, since there are no chemical reactions at these temperatures. They can run on solar cells when in sunlight, but when they are not in sunlight they will be dead and useless.

Novel by the name The Invincible - http://en.wikipedia.org/wiki/The_Invincible [wikipedia.org] . Blows my mind how much modern and "future" science is guided by the vision of sci-fi writers of old. Have we had any original ideas in the last decade?!